Minimum Snow Slope Roof Pitch

Roof slope equivalents as rise.

Minimum snow slope roof pitch. The profile refers to the shape the metal sheets take when they bend to. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. Degrees to pitch rise in run table. Note that roof pitch is sometimes used in parallel with roof slope.

For example a roof with a 6 inch 12 pitch is one where it rises 6 inches vertically for every 12 inches of the horizontal run. The standing seam metal roof on this ice hockey rink leaked like a sieve a few weeks after the first snow arrived. In general determining the pitch of an existing roof is a simple calculation. A minimum slope of 1 inch per foot is recommended in snow country.

Importance of a roof pitch. Depending on the roof profile there are minimum roof slope requirements for each panel which need to be considered. The 1 4 inch per foot slope was not adequate. However roof pitch is technically measured and defined differently.

In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12. Low pitch roofs are seldom used in regions of severe weather due to the stress of snow accumulation on roofs of structures. This can be accomplished by measuring the number of inches the roof rises vertically for every 12 inches it extends horizontally. The minimum roof pitch for shedding snow is around 30 or a 6 12 or 7 12 slope although this is not a definite as the material of your roof the direction of the snow and wind are some factors that can affect whether or not snow will slide as roofs of as little as 10 have been reported to shed snow.

However you can only use this pitch with built up roofing or specialized synthetic roofing. Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. The minimum slope for standing seam of roof systems shall be one quarter unit vertical in 12 units horizontal 2 percent slope. The minimum roof pitch is also subject to the standards set forth by the various building codes used in the respective regions.

The chief reason for having a roof pitch is to redirect water and snow away from the roof and avoid any percolation that might result from stagnation of water on the roof. A minimum pitch of 3 in 12 or even 4 in 12 will normally be required. The following table provides the minimum required. There are some opinions that standing seam metal roof minimum slope is 12 but it increases the possibility of leaking on the few first days of snow arrival.